The present application relates to integrated circuits which can be configured into several very different functions after wafer fabrication, and more particularly to test mode control in such integrated circuits of this type.
As the constraints of low-power integrated circuits have steadily become tighter, the technique of power islands has become more important. In this technology some portions of an integrated circuit are powered up only on an “as-needed” basis. These individual sections are referred to as “power islands.”
In other applications (which are not admitted to be prior art to the present application), SanDisk inventors have described the technique of static or quasi-static power island selection to configure a control chip for any one of several external interface modes. For example, a memory control circuit which can be locally connected to a nonvolatile memory, and can also be configured to provide an external interface to USB, SD, or MS electrical standards.